I had a working system on a new laptop for few months already. Suddenly, I had a crash, got a black screen with lots of errors (which I am not sure I can reproduce). The problem is with the boot. When it starts grub it takes more time than usual (instead of a second it takes 6-7 seconds until the splash appears). After that, it starts to boot and fails with

Code:

!! Block device /dev/sda3 is not a valid root device...
!! Could not find the root block device in .
Please specify another value or: press Enter for the same, type "shell" for shell, or "q" to skip...
root block device() ::

I don't know what caused it. I did some updates, but didn't update yet udev to 191.

Currently, I am stuck with the message that it doesn't recognize root device.